Bulk-solidifying amorphous alloy compositions have been discovered within a variety of alloy systems. These materials are typically prepared by quenching a molten alloy from above the melt temperature to ambient temperature. Generally, cooling rates of 105° C./sec or lower have been employed to achieve an amorphous structure. Until the early nineties, the process-ability of conventional amorphous alloys was quite limited, and conventional amorphous alloys were readily available only in powder form or in very thin foils or strips with critical dimensions of less than 100 micrometers. In the early nineties, a new class of Zr- and Ti-based amorphous alloys was developed; these alloys had critical cooling rates less than 103° C./sec, and in some cases as low as 10° C./sec, much lower than comparable alloy systems discovered up to that point. Bulk-solidifying amorphous alloys have very high strength, high specific strength, high elastic strain limit, and an unusual combination of other engineering properties.
Amorphous alloys and their in-situ composites generally need high purity constituent elements to achieve optimum mechanical and thermal properties. However, the need for high purity elements limits the number of re-melting and recycling steps to which the alloys can be subjected. This not only increases the cost of manufacturing, but also increases the waste and environmental pollution associated with such manufacturing.
Accordingly, there is a need to develop a new class of engineering alloys that exhibit the same thermal and mechanical properties (e.g., high yield strength, high hardness, high ductility and toughness), yet have a reduced manufacturing cost and environmental impact.